The invention relates to an apparatus on a flat card or roller card for grinding a fibre processing clothing that is disposed on a rotating roller or a card flat.
It is known to provide an apparatus having grinding equipment with at least one grinding element and an infeed device serving to position the grinding element against the clothing, the degree of infeed being adjustable and detectable.
In practice, grinding of the cylinder or the card flat is carried out in accordance with the approximate guidelines of the machine supplier or clothing manufacturer. These guidelines constitute a compromise between the many clothings used. If one considers the card flat, a typical grinding instruction states: apply to flat to produce scratch contact and infeed 4/1000″. By the same token, these instructions attempt to convey to the operator pointers for efficient grinding on the basis of criteria relating to flying sparks and grinding noise. The practical application of grinding cannot be specifically represented in this way. In addition, the specific state of the clothing can only be given inadequate consideration, and the untrained operator has great problems in identifying whether he is grinding correctly.
In the case of a known apparatus (EP 0 957 188 A), grinding is effected by slowing advancing a grinding cylinder using a micrometer screw, until a slight grinding noise is audible. Depending on the type of clothing wires, grinding sparks occur. Once the grinding noise or the grinding sparks occur uniformly over the entire length of the card flat bar and the clothings of the card flat bar, this is an indication that all clothing wires have been subjected to the action of the grinding equipment and have been sharpened. The disadvantage of this procedure is that detection of the degree of infeed and the grinding intensity (contact pressure) is effected purely visually, and this is moreover dependent on the experience of the person carrying out the adjustment. An optimum and reproducible grinding operation is not possible in this manner.